WOBURN (CBS) – Investigators are having trouble identifying the one man they have in custody in connection with Tuesday’s shooting of a Woburn police officer.

Officer Robert DeNapoli, 51, was shot multiple times during an attempted jewelry store robbery. He surivived, but is expected to have a long recovery.

View: Photos Of The Scene And Search

The gunman and as many as three others escaped.

One suspect was also wounded and was later arrested.

A tattoo on the back of the suspect (Photo courtesy: Middlesex D.A.'s office)

“The defendant remains hospitalized in serious condition as a result of injuries he sustained at the time of the incident. Authorities have not yet been able to identify the man, who had no identifying information on his person when he was apprehended,” Middlesex District Attorney Gerry Leone said in a statement Thursday.

Another tattoo on the suspect (Photo courtesy: Middlesex D.A.'s office)

Police released two photos of the man’s tattoos, hoping someone will recognize him.

One tattoo on the man’s arm is called an ankh, a symbol of life.

The other on his back is an elaborate design with Spanish words translating to “The world is mine.”

They haven’t released a photo or description of him or a description of the other suspects at this point in the investigation.

Anyone with information should call police at 781-897-6650 or 781-933-1212.