DENVER (CBS4)– The teenager arrested in connection with the murder of a cab driver will not be charged, at least for now.

Although the teenage suspect remains at the center of the investigation, the Denver District Attorney’s Office did not have enough evidence to file formal charges. Investigators only had 72 hours to hold the teen on suspicion of murder.

“We were on a deadline to go forward with the charges so at this point we have declined charges,” said DA spokeswoman Lynn Kimbrough.

Darren Bloomquist, 49, was shot and killed in his cab after receiving a call to 20000 East Mitchell Place in Green Valley Ranch on Sept. 5 According to Metro Taxi, Bloomquist was shot in the head during a robbery.

Darren Bloomquist (credit: Metro Taxi)

Darren Bloomquist (credit: Metro Taxi)

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The teen was identified as a suspect 10 days later while he was in custody on an unrelated warrant. He remains in custody on that warrant.

“It means right now they don’t feel like they have enough and want to keep doing more investigation,” said CBS4 Legal Analyst Karen Steinhauser.

Steinhauser said not filing charges now preserves the options that prosecutors have in the future.

“Prosecutors could even convene a grand jury if they felt like people were not cooperating so by him not being in custody they’re actually giving themselves more time to do a thorough conviction,” said Steinhauser.

Records in the case have been sealed. The suspect has not been identified because he is a juvenile.

Bloomquist had taken the job moonlighting as a cab driver to help pay medical bills for his disabled wife.