At about 5:00 P.M. on January 25, 1966, on Erie Street, S.E., three men assaulted and robbed James Warwick of a wallet, approximately $200 in cash, and two checks payable to Warwick’s employer, W. A. Dawson. Immediately after the attack on Warwick, a motorist, Donald R. Leigh, saw three Negro males running from the scene of the robbery. Though he did not then know that a crime had been committed, Leigh did notice that the three men jumped into a blue 1953 or 1954 Chevrolet hardtop. Subsequently, after he came to the aid of Warwick, the District of Columbia police arrived and Leigh gave them this description of the car and the men.
At about 5:20 P.M., the police broadcast a radio lookout for three male Negroes in a 1953 blue Chevrolet wanted in connection with the robbery and assault on Erie Street. Shortly thereafter Police Officer Bailey, who was stationed about 3.7 miles from Erie Street, spotted a blue 1954 Chevrolet hardtop, occupied by four Negro males, heading away from the direction of the crime. Unable to follow, the officer broadcast his observation, including the D.C. license plate number of the car. Police headquarters also issued a supplemental lookout describing the occupants of the car as Negro males in their late teens or early twenties wearing dark clothing.
Officer Stone and his partner, who were cruising in Officer Bailey’s area, heard both the initial lookout and the Bailey broadcast. Stone soon spotted the car Bailey had observed and followed it for several blocks while awaiting other squad cars summoned to the area. At around 5:40 P.M., at 14th and C Streets, N.E., about six miles from the robbery, Officer Stone’s squad car forced appellants’ car to the side of the road while two other police cars blocked it from the front and rear. Officer Stone approached appellants’ car, apparently with his gun in hand, and ordered the occupants to sit still and keep their hands in plain sight. He then opened the front door on the driver’s side and asked the driver, appellant Russell, for his driver’s permit. As the officer was returning the permit he noticed a wallet on the right side of the floor of the car. He then went to the other side of the car, opened the door, and retrieved the wallet. In it were the two checks payable to W. A. Dawson. The appellants were then frisked on the scene and taken to the precinct house where they were thoroughly searched. Each had between $55 and $91 in cash. They were then placed in a lineup, after which Warwick stated that the clothing of three of them, appellants Frye, Bailey and Oliver, resembled that worn by his three assailants.
*308Before trial there were three separate hearings on motions to suppress filed in behalf of the appellants. Three different judges heard the motions and decided that the evidence seized from the car and from appellants was admissible. At the ensuing trial before a fourth judge the Government offered in evidence the items seized, including the stolen wallet and the money found on each of the appellants. Appellants’ objection to the offer was overruled by the trial judge, appellants were convicted, and these appeals followed.
Essentially three issues are raised on appeal. First, all appellants contend that the seized stolen items should not have been admitted in evidence. Second, each urges that there should have been a directed verdict of acquittal for insufficient evidence in that each may have been the fourth occupant of the ear, seen by neither Warwick nor Leigh. Third, appellant Frye argues that he should have been permitted to testify at the hearing on his motion to suppress without waiving his Fifth Amendment right not to incriminate himself.
(1) Admissibility of the evidence.
The Fourth Amendment1 prohibits unreasonable searches and seizures, but it is well established that a search incident to a lawful arrest is permissible even without a warrant. Weeks v. United States, 232 U.S. 383, 392, 34 S.Ct. 341, 58 L.Ed. 652 (1914). This right unquestionably extends to a contemporaneous search of the car in the control of the accused at the time of arrest. Preston v. United States, 376 U.S. 364, 367, 84 S.Ct. 881, 11 L.Ed.2d 777 (1964). The arrest which justifies the search, however, is lawful only if the Fourth Amendment standard of probable cause is met. Beck v. State of Ohio, 379 U.S. 89, 91, 85 S.Ct. 223, 13 L.Ed.2d 142 (1964). And there must be probable cause before the search begins, for “a search is not to be made legal by what it turns up. In law it is good or bad when it starts and does not change character from its success.” United States v. DiRe, 332 U.S. 581, 595, 68 S.Ct. 222, 229, 92 L.Ed. 210 (1948). This is true even when the arrest or search is made pursuant to a warrant. Where, as here, the arrest is made without a warrant the standard is at least as high. Wong Sun v. United States, 371 U.S. 471, 479-480, 83 S.Ct. 407, 9 L.Ed.2d 441 (1963); Beck v. State of Ohio, supra, 379 U.S. at 96, 85 S.Ct. 223.
Though the arresting officers here did not think that a formal arrest took place until after the stolen wallet was spotted, seized and examined, the Government, as in Henry v. United States, 361 U.S. 98, 103, 80 S.Ct. 168, 4 L.Ed.2d 134 (1959), concedes that in law the arrest of the car’s passengers as well as its driver took place at the time Officer Stone approached the car, perhaps with gun drawn, and told appellants to sit still and keep their hands in plain sight. Even if the formal arrest was not made until after the search, the search will be upheld so long as there is probable cause for an arrest before the search is begun. See United States v. Gorman, 2 Cir., 355 F.2d 151, 159-160 (1965), cert. denied, 384 U.S. 1024, 86 S.Ct. 1962, 16 L.Ed.2d 1027 (1966). Accepting the Government’s concession, the question then is whether there was probable cause for an arrest when Officer Stone first approached appellants’ ear. We think that there was.
Probable cause is a plastic concept whose existence depends on the facts and circumstances of the particular case. It has been said that “ ‘[t]he substance of all the definitions’ of probable cause ‘is a reasonable ground for belief of guilt.’ ” Brinegar v. United States, 338 U.S. 160, 175, 69 S.Ct. 1302, 1310, 93 L.Ed. 1879 (1949). Much less evidence *309than is required to establish guilt is necessary. Draper v. United States, 358 U.S. 307, 311-312, 79 S.Ct. 329, 3 L.Ed. 2d 327 (1959). The standard is that of “a reasonable, cautious and prudent peace officer” and must be judged in the light of his experience and training. Bell v. United States, 102 U.S.App.D.C. 383, 387, 254 F.2d 82, 86, cert. denied, 358 U.S. 885, 79 S.Ct. 126, 3 L.Ed.2d 113 (1958). The police must have enough information to “warrant a man of reasonable caution in the belief” that a crime has been committed and that the person arrested has committed it. Carroll v. United States, 267 U.S. 132, 162, 45 S.Ct. 280, 288, 69 L.Ed. 543 (1925). See also Henry v. United States, supra, 361 U.S. at 102, 80 S.Ct. 168. A finding of probable cause depends on the “practical considerations of everyday life on which reasonable and prudent men, not legal technicians, act.” Brinegar v. United States, supra, 338 U.S. at 175, 69 S.Ct. 1310.
We think the police acted reasonably in this case. They knew that a robbery had been committed by three Negro men who had then escaped in a 12- or 13-year-old car of which they had an apparently accurate description. They also had a general description of its occupants. A car matching this description was then seen at a time and distance from the robbery consistent with its being the getaway car. It was effective law enforcement which enabled the police to cordon off the suspects’ car and avoid the hazards of a high speed chase. Clearly this was not an arrest for investigation of the kind we condemned in Gatlin v. United States, 117 U.S.App.D.C. 123, 326 F.2d 666 (1963). The police here were obviously quite certain they had the right men. And, most important, there is no suggestion of a roundup of innocent “suspects” following the robbery.
We do not think it significant that the vintage blue car stopped here had four occupants while the lookout was for three suspects. The police could reasonably suppose that a fourth man, serving as a lookout, had waited in the car while the other three perpetrated the robbery itself. Nor do we think it significant that a 1954 Chevrolet was stopped while the lookout was for a 1953 Chevrolet, for the record shows the two models are very similar. Even wider discrepancies between the description in the police lookout and the man arrested were present in Brown v. United States, 125 U.S.App.D.C. 43, 365 F.2d 976 (1966), where this court sustained the denial of a motion to suppress on facts similar to those of this case.
Had the police waited for more detailed information before making the arrests, the suspects’ identities might never have been ascertained or the car might have sped on into one of the neighboring jurisdictions. The “exigencies of the situation made [the police] course [of action] imperative.” See McDonald v. United States, 335 U.S. 451, 456, 69 S.Ct. 191, 193, 93 L.Ed. 153 (1948). As the Supreme Court said last term in Warden, Md. Penitentiary v. Hayden, 387 U.S. 294, 298-299, 87 S.Ct. 1642, 1646, 18 L.Ed.2d 782 (1967), “The Fourth Amendment does not require police officers to delay in the course of an investigation if to do so would gravely endanger their lives or the lives of others. Speed here was essential * * So too in our case was speed essential if the suspected perpetrators of the robbery and brutal assault were to be captured. The emergency character of these arrests weighs heavily in determining their reasonableness. “Common sense dictates, of course, that questions involving searches of motorcars or other things readily moved cannot be treated as identical to questions arising out of searches of fixed structures like houses. For this reason, what may be an unreasonable search of a house may be reasonable in the ease of a motorcar.” Preston v. United States, supra, 376 U.S. at 366-367, 84 S.Ct. at 883. See also Cooper v. State of California, 386 U.S. 58, 87 S.Ct. 788, 17 L.Ed.2d 730 (1967); Price v. United States, 121 U.S.App.D.C. 62, 348 F.2d 68, cert. denied, 382 U.S. 888, 86 S.Ct. 170, 15 L.Ed.2d 125 (1965). The element of flight in a vehicle from the scene of the *310crime tips the scales here in favor of probable cause. Carroll v. United States, supra; Brinegar v. United States, supra. Compare Johnson v. United States, 333 U.S. 10, 14-15, 68 S.Ct. 367, 92 L.Ed. 436 (1948); McDonald v. United States, supra, 335 U.S. at 454-456, 69 S.Ct. 191.
(2) Sufficiency of the evidence.
Each appellant relies on this court’s decision in Goodwin v. United States, 121 U.S.App.D.C. 9, 347 F.2d 793, cert. denied, 382 U.S. 920, 86 S.Ct. 298, 15 L.Ed.2d 234 (1965), to argue that the trial judge erred in not directing a verdict in his favor. The facts in Goodwin are much like those of this case. In Goodwin the four occupants of a getaway car were arrested about an hour after the robbery of a grocery store. A search of the car turned up the stolen money as well as the gun used to threaten the store’s proprietor. There, as here, the robbery itself was committed by only three men, but there the victim positively identified three of the four suspects as his assailants. The fourth, unidentified, defendant, Paul Vaughn, testified at trial and denied his participation in the crime. Nevertheless, all four were convicted. On appeal this court reversed Vaughn’s conviction on the ground that there was not enough evidence to establish “beyond a reasonable doubt that he had been the look-out man. Nor was [his] presence in the car at the time of the arrests sufficient, we think, to show that he was in possession of the recently stolen articles here involved.” 121 U.S.App.D.C. at 11, 347 F.2d at 795.
In the instant case there was not a positive identification made of any of the suspects, and each argues that he is the fourth man, standing in the shoes of Paul Vaughn. This argument is stressed particularly by appellant Russell. We think that the Goodwin case, though similar, is sufficiently different in two significant respects to require an affirmance of all four convictions in this case. First, the only suspect who was not even tentatively identified as a participant in the actual assault and robbery was the driver, Russell. That he was the driver, and not a passenger in the back seat as Vaughn was, makes his presence more consistent with his being a lookout than with his being an innocent passenger who joined the others after the crime was committed. Second, and more important, each of the appellants here was found with what was almost certainly part of the loot in his immediate possession. This was not true in Goodwin, where all the money was found in a plastic bag on the floor of the car and there was no evidence that Paul Vaughn was going to participate in its distribution. Though the cash here was fungible and could not be identified by serial number or denomination, unless the money found on each of the four appellants is cumulated, all the stolen funds cannot be accounted for. Thus the inference of guilt from the possession of recently stolen articles is much stronger here than it was in Goodwin, and is sufficiently strong, with the other circumstances pointing toward guilt, to require affirmance. Cf. Norman v. United States, 126 U.S.App.D.C. 387, 379 F.2d 164, cert. denied, 389 U.S. 886, 88 S.Ct. 167, 19 L.Ed.2d 186 (1967).
(3) Self-incrimination.
Appellant Frye’s attorney apparently intended to put his client on the stand at the hearing on his motion to suppress. He declined to do so, however, when the District Court judge ruled that whatever Frye said there could be used against him at trial. On appeal Frye argues that he should have been allowed to testify at the hearing without waiving his Fifth Amendment privilege not to incriminate himself. We agree.
It is the rule in this jurisdiction that the defendant can challenge the voluntariness of his confession outside the jury’s presence without waiving his privilege against self-incrimination. Wright v. United States, 102 U.S.App. D.C. 36, 45, 250 F.2d 4, 13 (1957). There is no sound reason why the rule should be different where the defendant challenges the admissibility of non-testimonial evidence at the hearing on his motion to suppress. The Government contends that Wright holds only that where the *311defendant successfully challenges the vol-untariness of his confession his testimony at the hearing is inadmissible at trial. We do not read this limitation into Wright. There we said, simply and unequivocally, that “[t]o substantiate a defendant’s contention that his confession was involuntary, it is generally necessary for him to take the stand. Since it is a matter of course that the defendant should be allowed to testify to the involuntariness of his confession without waiving his privilege against self-incrimination, 3 Wigmore, Evidence 345 (3d Ed. 1940), it follows that, when he requests it, he should be given a hearing without the jury.” Ibid.
The Government also relies on a series of cases2 from other circuits to argue that, whatever the Wright rule may be as to voluntariness hearings, the law concerning the use of the defendant’s testimony taken at a Rule 41(e), Fed.R.Crim.P., hearing to suppress evidence is clear — if the defendant testifies and loses on his motion to suppress, his testimony can be used substantively against him at trial. The Government concedes that under this rule “in some cases a defendant wishing to challenge the legality of a search may find himself, on the horns of a dilemma, having to incriminate himself to assert his claim of illegality,” but argues that this is not a dilemma of the Government’s making.
Most of the cases cited by the Government in support of this proposition antedate the decision in Jones v. United States, 362 U.S. 257, 80 S.Ct. 725, 4 L.Ed.2d 697 (1960), where the Supreme Court rejected a whole line of Court of Appeals cases and held that a defendant had standing under Rule 41(e) to challenge the legality of a seizure of narcotics without admitting ownership. Prior to Jones the defendant’s dilemma was not of the Government’s making either, but the Court nonetheless dissolved it, holding that the exercise of a constitutional right cannot be embarrassed by placing the defendant in such a position.
We think the implications and logic of Jones require that the testimony of the defendant taken at the suppression hearing, although admissible for impeachment, cannot be used affirmatively against him at trial. 362 U.S. at 261-265, 80 S.Ct. 725. The Fourth Amendment protection against unreasonable searches and seizures is not a stepchild of the Constitution,3 nor is the privilege against self-incrimination. There is no reason why the defendant should be forced to risk waiving the one in order to raise the other. Compare Garrity v. State of New Jersey, 385 U.S. 493, 87 S.Ct. 616, 17 L.Ed.2d 562 (1967). Were we to adopt the Government’s rule many unlawful searches and arrests would go unchallenged.
We do not, however, reverse in this case because, applying the rule of Chapman v. State of California, 386 U.S. 18, 87 S.Ct. 824, 17 L.Ed.2d 705 (1967), we find beyond a reasonable doubt that appellant Frye was not prejudiced. The only issue at the hearing on his motion to suppress was whether the police had probable cause to make an arrest. In his brief on appeal Frye argues that he would have testified on the question of just when the arrest occurred. Assuming that the suspect’s frame of mind is relevant to a determination of this issue, *312Frye could not have been prejudiced since we have found that there was probable cause at the earliest possible time the arrest can in law be said to have been made. At oral argument, Frye’s attorney stated that, at the hearing on the motion to suppress, Frye would have testified that he joined the others after the robbery occurred and played no part in it. But clearly such evidence is not relevant to the question whether the police had probable cause to arrest the occupants of the car. If Frye wished to testify as to his non-participation, he should have done so at trial.
We have considered the other points urged on appeal and find them to be without merit.
Affirmed.
. U.S.Const. Amend. IV:
“The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.”
. United States v. Taylor, 4 Cir., 326 F.2d 277, cert. denied, 377 U.S. 931, 84 S.Ct. 1332, 12 L.Ed.2d 295 (1964); Monroe v. United States, 5 Cir., 320 F.2d 277 (1963), cert. denied, 375 U.S. 991, 84 S.Ct. 630, 11 L.Ed.2d 478 (1964); Fowler v. United States, 10 Cir., 239 F.2d 93 (1956); Kaiser v. United States, 8 Cir., 60 F.2d 410, cert. denied, 287 U.S. 654, 53 S.Ct. 118, 77 L.Ed. 565 (1932); Heller v. United States, 7 Cir., 57 F.2d 627, cert. denied, 286 U.S. 567, 52 S.Ct. 647, 76 L.Ed. 1298 (1932); Connolly v. Medalie, 2 Cir., 58 F.2d 629 (1932). See also United States v. Garrett, 7 Cir., 371 F.2d 296 (1966), cert. granted, sub nom. Simmons v. United States, 388 U.S. 906, 87 S.Ct. 2108, 18 L.Ed.2d 1345 (1967).
. See Mr. Justice Frankfurter’s ringing dissent in United States v. Rabinowitz, 339 U.S. 56, 68-71, 70 S.Ct. 430, 94 L.Ed. 653 (1950).