is he joined in our group vs he joined our group

Some examples from the web:

• He joined some group to help him be more honest.
• Under questioning, Yolanda admitted she was upset about your inability to contain a certain someone who has taken up all of the oxygen since he joined the group.
• He joined a group to try and, like, talk to the Muslims.
• Once the document was finished, a sixth group joined in.
• He joined a music group and plays the flute
• Mr President, our group has joined with other groups to hold a debate on Mediterranean policy, and I cannot deny that this initiative stems from a two-fold concern.
• The Calling began as part of the group I joined in Syria.
• Since Mr Podestà joined our group, we have the number of VicePresidents that we need.
• He joined some jihadi-inclined group in Chechnya, snuck into the States two weeks ago.
• Our group joined with the Group of the European People's Party (Christian Democrats) and European Democrats in voting for this paragraph to be deleted.
• Will joined a group called The Garden.
• The father seems to share the same anti-government bent as his son, and when junior got incarcerated, he joined an extremist group called the patriot front.
• She joined a group of Navy corpsmen working with missionaries to provide free immunizations to villagers in the local mountains.
• The same night, they joined a group trying to escape via the sewers.
• I joined this group for this jam.
• She joined this group last year.
• I'm so glad you joined the group.
• University students joined neighborhood groups and labor unions.
• I've joined a group, Joe.
• Once your man has joined the group, society has lost him.

Some examples from the web:

• Since Mr Podestà joined our group, we have the number of VicePresidents that we need.
• He joined some group to help him be more honest.
• Under questioning, Yolanda admitted she was upset about your inability to contain a certain someone who has taken up all of the oxygen since he joined the group.
• He joined a group to try and, like, talk to the Muslims.
• Maybe it wouldn't be the worst thing if a baby joined our little group.
• He joined a music group and plays the flute
• Mr President, our group has joined with other groups to hold a debate on Mediterranean policy, and I cannot deny that this initiative stems from a two-fold concern.
• He joined some jihadi-inclined group in Chechnya, snuck into the States two weeks ago.
• Our group joined with the Group of the European People's Party (Christian Democrats) and European Democrats in voting for this paragraph to be deleted.
• Will joined a group called The Garden.
• Maybe it wouldn't be the worst thing if a baby joined our little group.
• The father seems to share the same anti-government bent as his son, and when junior got incarcerated, he joined an extremist group called the patriot front.
• She joined a group of Navy corpsmen working with missionaries to provide free immunizations to villagers in the local mountains.
• The same night, they joined a group trying to escape via the sewers.
• I joined this group for this jam.
• She joined this group last year.
• I'm so glad you joined the group.
• University students joined neighborhood groups and labor unions.
• I've joined a group, Joe.
• Once your man has joined the group, society has lost him.